Getters are absorbent compositions often used within a sealed enclosure forming part of, or a housing for, the electrical or electronic device, to remove unwanted materials from the atmosphere within the enclosure. Getter compositions for the removal of hydrogen are already known. For example, unsaturated organic compounds may be used as hydrogen getters, optionally in a composition including a hydrogenation catalyst. In U.S. Pat. No. 6,428,612 B—, a hydrogen getter is described comprising a particulate zeolite having a portion of its sodium ions exchanged by an activated metal such as silver. The getter is provided in a flexible hydrogen permeable, moisture-impermeable sheet material in combination with a moisture absorber. U.S. Pat. No. 4,559,471 A—. describes the use of getter auxiliary means for decomposition of hydrocarbons within evacuated apparatus in which the getter auxiliary means comprises an inorganic porous carrier charged with one or more of rhodium, copper, platinum, palladium and their oxides. U.S. Pat. No. 6,200,494 B—. describes a combination of getter materials comprising a mixture of an oxide of a transition metal, metallic palladium and a moisture absorbing material.